@liemph; I'd be happy to share my code, but all the GPS-related parts can be found in the product examples here:
https://github.com/m5stack/M5Stack/tree/master/examples/Unit/GPS_AT6558
The example is pretty complete, but unreadable.

The project I'm working on is more display oriented, and most of the code is a nascent control class I'm playing around with for solving general display problems. You're welcome to take what you like from it:
https://github.com/vkichline/GPSTest

I plan to pursue the display controls in another project, so I won't be updating this one.

Thanks a lot.

The project I'm working on is more display oriented, and most of the code is a nascent control class I'm playing around with for solving general display problems. You're welcome to take what you like from it:
https://github.com/vkichline/GPSTest

I plan to pursue the display controls in another project, so I won't be updating this one.

• Unplug the GPS unit from Port C.
• Stat the M5Stack FIRE.
• Plug the GPS Unit back into Port C.

Without unplugging the GPS unit I experience 100% failures.
With unplugging before power-up: 100% success.

The unit is a beauty when working! Acquires 10 satellites in seconds, indoors!
The power-up sequence is definitely a drawback, but not a deal breaker.
I wonder if it could be solved with a capacitor or some other simple augmentation?

@m5stickfreakler if the "old" GPS has problem, pls contact our store.

I bought a GPS Unit from Aliexpress and it seems old since I faced the same problem with @M5StickFreakler. What store should I contact for this issue?
Just now I contacted the M5Store from the Aliexpress homepage.

start takes time, (maybe 3~5min). the signal quality very important , so had better use it in the house outside.

Thank you very much.
Unfortunately it does not work with any port as I have described above.
I just receive Quality "NO signal". It can stay for hours outside, nothing changes.
Cold start time is 35 seconds as you can see in technical details of m5stack.

BUT HERE IS THE BEST:
I received today 4 new GPS Units and now it works.
My "old" two GPS units are not working.
That was it. A lot of waited time

Hint: if you use the forum search feature you can find threads like this that say the M5Stack Fire PSRAM conflicts with port C because they use the same GPIO 16 and 17, which is also the same ports the GPS units and modules use (see the GPS docs). The work around involves cutting a trace and rewiring.

Thank you
But I would like to get a solution from M5Stack withouth cutting wires in all my devices.
M5Stack sell this GPS units to use 'em on M5Stack devices and does not provide any information that we have to modify the hardware to get running it.
Also I do not use the GPS Modul, but I use the GPS Unit!

@m5stack could you provide customers with any official information about the behavior?

Best regards
Thomas

@M5StickFreakler what firmware are you running on your devices?
I am checking through items at the moment and finding problems due to the switch to the mainstream micropython branch.

Hi ajb2k3

I have checked it with UIFLOW 1.0.9.1 and following firmwares

• 1.2.3 --> not supported
• 1.3.2 --> NOK
• 1.4.4 --> NOK
• 1.4.5 --> NOK
• 1.4.5.1 --> NOK
• 1.5.0 --> NOK
• 1.5.1 --> NOK

Nothing is working. I have tested it on 3 different M5Stack FIRE with 3 different GPS units.
Each on all ports - nada

It is very frustrating and time consumpting and costly. I think M5Stack should increase its quality standards. Here in Switzerland, we are used to the fact that products work what they promise and what we pay for.

Best wished
Thomas

I haven't personally used the gps unit, but as I am aware it communicates via UART which means it should be connected to port C

It does not work on port C.
In UIFlow you can switch between Port A, B, and C for the GPS-Unit, so it suggest that all three ports are possible to use.
But it does not work, neither with A, B nor C.
I have here M5Stack stuff for over thousand dollar and many, many items are not working well.
So, I hope there is a solution to get working the GPS unit(s).

https://forum.m5stack.com/topic/1798/issue-with-port-c-uart-of-m5stack-fire-finger-unit-ok-but-gps-no-good/2